Commit | Line | Data |
---|---|---|
2ce81398 DS |
1 | #if defined(LIBC_SCCS) && !defined(lint) |
2 | static char sccsid[] = "@(#)frexp.c 5.2 (Berkeley) %G%"; | |
3 | #endif LIBC_SCCS and not lint | |
b8f253e8 | 4 | |
29aaea38 | 5 | /* |
b8f253e8 KM |
6 | * the call |
7 | * x = frexp(arg,&exp); | |
8 | * must return a double fp quantity x which is <1.0 | |
9 | * and the corresponding binary exponent "exp". | |
10 | * such that | |
11 | * arg = x*2^exp | |
12 | * if the argument is 0.0, return 0.0 mantissa and 0 exponent. | |
13 | */ | |
29aaea38 BJ |
14 | |
15 | double | |
16 | frexp(x,i) | |
17 | double x; | |
18 | int *i; | |
19 | { | |
20 | int neg; | |
21 | int j; | |
22 | j = 0; | |
23 | neg = 0; | |
24 | if(x<0){ | |
25 | x = -x; | |
26 | neg = 1; | |
27 | } | |
be56fc55 RC |
28 | if(x>=1.0) |
29 | while(x>=1.0){ | |
29aaea38 BJ |
30 | j = j+1; |
31 | x = x/2; | |
32 | } | |
be56fc55 | 33 | else if(x<0.5 && x != 0.0) |
29aaea38 BJ |
34 | while(x<0.5){ |
35 | j = j-1; | |
36 | x = 2*x; | |
37 | } | |
38 | *i = j; | |
39 | if(neg) x = -x; | |
40 | return(x); | |
41 | } |